Sliding vane pump



E. G. SEASTROM l SLIDING VANE PUMP I s sheets-She@lc 1 Feb. 28 195o Feb. 28, 1950 E'. G, sEAsTRQM 2,498,929

SLIDING VANE PUMP Filed July 3, 1947 3 Sheets-Sheet 2 Feb. 28, 1950 E. G. sEAsrRoM 2,498,929

SLIDING VANE PUMP Filed July 3. 1947 3 Sheets-Sheet 3 Patented Feb. -28, 1950 2,498,929 sLmING'vANE PUMP Erik G. Seastrom, Easton, Pa., assignor to Treadwell Engineering Company, Easton, Pa., a corporation of Pennsylvania Application July 3, 1947, Serial No. 758,871

17 claims. l

This invention relates to pumps and more particularly to the general class of combined centrifugal and displacement pumps, exemplified in my copending application Serial No. 580,871, filed March 3, 1945, and the present application comprises a continuation-impart of that application.

The general object of the invention is to provide, in connection with a pump ofy this type, certain novel features which cooperate to afford greater mechanical efficiency and smoothness of operation and to improve the hydraulic drive of the hollow eccentric discharge ring or sleeve, by reducing friction, equalizing pressure on moving parts, providing better bearing support for rotating members, effecting self-lubrication by means of the working liquid, protecting the moving mutually contacting parts against damage from foreign particles, sealing certain of the parts against leakage, and compensating for wear.

In its preferred embodiment, the invention contemplates the provision of a substantially cylindrical pump housing having an axial inlet connection at one' end and a radial or tangential outlet arrangement near the opposite end. A cylindrical working chamber is disposed between the inlet and discharge portions of the housing,

and a hollow impeller hub rotates in said chamber. A hollow vane element 'extends radially from said impeller hub and its outer edge sweeps the inner wall of the chamber. An eccentrically mounted hollow discharge ring or sleeve has rolling contact with both the impeller hub and the wall of the working chamber and serves to divide the latter into lune-shaped sub-divisions, all as fully described in the copending application to which reference has been made. In accordance with the present invention, novel eccentric floating bushings are interposed between the ring and the impeller hub, liquid seal grooves are provided on certain of the bearing surfaces of the casing, and on the rolling contact surfaces of the sleeve or of the impeller hub, and passageways are established to conduct a certain amount of seepage from the high pressure to the low pressure side of the pump which seepage serves to lubricate and to seal the moving parts.

The impeller assembly, including the hollow fluid receiving hub, the distributing v ane, and

the eccentric hollow sleeve, is driven by an axial drive shaft which is mounted in anti-friction bearings and may be constructed integrally with the impeller hub. In the illustrated embodimentv of the invention, only one anti-friction bearing 2 assembly is provided and that beyond the outer end of the working chamber, the shaft thus having a sort of cantilever or overhung suspension.

the projecting end of the shaft comprising the impeller hub rotating in the eccentric floating bushings which are keyed to' the housing and serve to separate the hub and the eccentric ring.

In certain of the practical embodiments, novel sealing means are provided at the points of rolling contact between the hub and ring, and be- ,tween the ring and the chamber wall, the sealing element for the latter point being more appropriately designated a wiper," this element being preferably non-metallic, non-abrasive, and pliable, and serving to prevent damage to the rolling surface by any foreign particles which may be in the pumped fluid. Novel means are also provided for applying the wiper or seal to the contacting surface with regulated pressure.

Another object is to provide a pump of the class described which is so constructed and arranged thatthe driving of the eccentric sleeve by the vane carried by the drive shaft, is effected by hydraulic pressure alone, no mechanical connection being necessary under most conditions of operation.

Another feature of novelty is the mounting of the Vane with respect to the impeller hub so that it bears radially outwardly against the chamber wall with a certain resiliency and thus automatically adjusts or compensates itself for wear.

It will be understood, of course, that by reversal of the mode of operation, the pump may be converted into a hydraulic motor, and thus the drive shaft becomes a driven shaft or power take-ofi', and the pumped liquid becomes the motive fluidi Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which certain embodiments of the invention are illustrated by way of example.

In the drawings,

Figure 1 is a view in horizontal section of the pump embodying certain of the principles of the invention;

Figure 2 is a vertical longitudinal sectional view of the pump, the plane of section passing through the impeller Vane;

Figure 3 is a view in end elevation of the pump housing;

Figures 4 to 11 inclusive are transverse sectional views through the working chamber at or near its mid-point, showing successive positions of the various operative parts during a single cycle;

Figure 12 is a sectional view', similar to Figure amaca@ of a slightly different embodiment of the pump; Figure 13 is a transverse sectional view taken on line l3-I3 of Figure 12; and

Figure 14 is a similar view showing some further modifications of the pump, which may be applied to any of the embodiments ofthe invention.

Referring first more particularly to Figures 1 to 11'of the drawings, it will be seen that the novel pump comprises a casing or housing I6 of a generally cylindrical configuration to which is secured an end plate or closure l I. The housing or casing I preferably comprises an integral casting which also includes the enlarged centrifugal exhaust casing I2 and the smaller cylindrical anti-friction bearing containing portion i3. The housing proper encloses a cylindrical working -chamber I5 within which the impeller organization is adapted to rotate. g The cover plate I I is provided with an axial nipple I6 within which the end of the inlet pipe l1 is disposed. The portion l2 of the casing encloses the centrifugal outlet or discharge chamber I8 of expanding cross section into which the working liquid is passed from the main chamber I5 by means which will be presently described. A discharge conduit is shown at l5.

Within the bearing extension i3 of the housing there is disposed the spaced anti-friction bearing assemblies and 2 i, bushings 22 being interposed between the respective races of these assemblies and the whole bearing organization being retained within the casing E3 by means of the annular rings or anges 23 and 24 carried respectively by the inner wall of the casing i3 and the drive shaft 25.

The drive shaft passes through an opening in the end plate 26 of the casing and packing 21 provides a, stumng box therefor. Suitable driving connections are provided vupon the projecting end of the shaft 25 or, in the event that the device is operating as a motor instead of a pump, suitable power take-oir transmissions are connected to the shaft.

From the anti-friction bearing the shaft extends toward the right in Figure 1; and upon the end thereof which projects into thel working chamber I5 there is formed the hollow impeller hub 3G. The hollow interior 3I of this hub faces the inlet conduit I1 and is adapted to receive the ilud which enters therethrough. As best shown in Figures 4 to 11 inclusive and in Figure 2, the hub 30 is provided with a longitudinal slot SIA in its wall within which is fitted a relatively broad and at radially extending impeller vane 32. The shank end of the vane which extends through the slot in the hub is provided internally of the hub with slots or grooves 33 in the outer side walls thereof. A partly cylindrical spring-metal keying element or clip 34 lies closely against the inner wall of the hollow hub 30 and has its edges inserted in the grooves 33 of the vane member 32, thus securely keying the vane to the impeller hub. The outer edge or margin of the vane 32 has a snug sliding fit as at 36 with the inner wall 31 of the working chamber I5.

Although the cylindrical inner wall surface 31 of the working chamber I5 is concentric with the shaft and impeller hub, there are provided at opposite ends of this chamber the eccentric bearing surfaces 40 and di, the one on a portion of the main casting of the housing I0 and the other` on the interior of the cover plate il. Disposed for rotation with the impeller assembly, within these eccentric bearing surfaces, is the hollow ring or sleeve 45. The eccentrically disposed ring or sleeve is longitudinally slotted along one numeral 46. It will be seen from inspection of Figures 4 to 11 inclusive that this opening 46 is somewhat wider than that which would be necessary to snugly receive the vane 32. The interior chamber 46 of the ring 45 is closed by the end wall i9 formed adjacent one side of the slot 46 but the opposite edge of the chamber is open as as 5i?. Referring to Figures 1 and 2 of the drawings, it will be seen thatsthe ring chamber 48 is provided with an end wall 52 toward the inlet end of the device but that somewhat restricted discharge passageways 53 lead endwise from the chamber 46 and then discharge radially into the centrifugal exhaust chamber i8.

In order to provide spaced bearing and guiding means between the eccentrically related hub 30 and ring d5, the floating eccentric bushings 55 and 56 are interposed at opposite ends of the impeller structure and within the bearing surfaces li and 4I. The bushings 55 and 56 are held stationary by means of the projecting lugs or keys 58 which are fitted in recesses in the end wall of the working chamber and in the cover plate I I.

AS clearly shown in Figure l of the drawings, the hollow impeller hub .3e is of a somewhat greater diameter than the drive shaft 25and between the shoulder 66 thus formed and a corresponding shoulder or ledge 6l on the housing there is disposed the packing 62. A nne bore or passageway 63 leading into space 3l, provides a vent to prevent the accumulation of pressure at the packing or seal 62. Similarly e. fine bore 65 is provided in the end wall 52 of the ring or sleeve d5 for the purpose of counteracting undue end thrust by means of liquid pressure. It should also be remarked that the bearing surfaces te and 4I within which the eccentric ring rotates are provided with small circular grooves 66 which provide a water seal and also aord lubricating means for the eccentrically mounted ring or sleeve 45.

Reverting again to Figures 4 to 1i inclusive of the drawings, it will be seen that .the outward corners of the side walls of the slot or opening 46 formed in the ring 45 are bevelled off slightly as suggested at 61 and 68. The outer end of the blade or vane 32 is provided with annular overhanging portions which at one instantaneous point in the operation of the device contacts the bevel portions 61 and 68 of the ring. This is shown in Figure 9 of the drawings.

The vane 32 is of peculiar construction comprising for the greater portion of its length the curved wall 10 which merges with one side margin of the vane at the inner edge. This construction -alords a passageway 12 through the vane vfrom the interior chamber 3l of. the hub 30 through which the liquid may pass into the working chamber I5. The configuration of the wall 10 .of the blade or vane 32 also affords on theopposite side of the vane -a cavity 15 which faces the inlet slot or opening 50 of the ring chamber 48.

Upon one side of the outer surface of the hub 30 adjacent the edge of the ring 45 which is provided with the opening 50, there is secured a sealing blade vor. strip 11, by any suitable means such as welding. The blade or flap 11 is secured at its inner edge and is received within a cutaway portion on. the surface of the hub, the free end 18 of the blade being normally sprung away from the hub and toward the inner wall of the ring 45 to the extent shown, for example, in Figuxes '7, 8,.9,and 10 of the drawings.. -The purpose 5 of this sealing element 'I1 is to seal of! the inne lune-shaped chamber formed between the hub 30 and the ring 45 when the parts are at or near the position shown in Figure 5 of the drawings. The sealing effect of this element begins'to come into operation shortly after the position indicated in Figure l1 and is adapted to continue through the positions shown in Figures 4, 5, and 6. The diametrically opposite position of the assembly is shown in Figure 9, where the edges 61, 68 are in sealing contact with the flanges adjacent the outer edge of the vane.

The operation of the pump is in general the same as described in my copending application Serial No. 580,871 to which reference has already been made. The liquid is drawn through the conduit II into the central chamber 3| of the hub and from thence it passes through the blade or vane passageway 'I2 during the rotation of the impeller assembly in the direction indicatedby the arrow in Figures 4 et seq. As clearly pointed out in the specification of the application referred to, the eccentrically guided ring I5 forms together with the walls of the impeller hub and the working chamber I5 oppositely facing interlocking lune-shaped working spaces L and L within the chamber I5. The vane 32 intersects these lune-shaped spaces and during its rotation the sub-division of these surfaces by means of the vanev continuously changes, the sub-division in advance of the blade continually diminishing and the sub-division behind the blade continually increasing in size. This phenomenon, of course, applies to both the inner and outer lune-shaped chambers L and L'. As the receding sub-chambers seek to enlarge behind the vane the uid is drawn through the passageway 'I2 and fills these sub-chambers. Similarly, as the sub-chambers in advance of the` blade continuallydiminish, the fluid passes through the cavity 'I5 in the forward face of the vane and through the opening 50 in the edge of the ring 45 into the ring chamber 48, from whence it is delivered through the passageway 53 into the centrifugal outlet chamber I8 and thence through the discharge conduit I9.

A careful consideration of Figures 4 to 1l of the drawings will reveal that the hollow ring 45 is, except for the momentary centered position shown in Figure 9, always spaced from the vane; However, the ring will undergo a constantly 4 changing position in relation to the continually moving impeller vane due to the existing equilibrium between hydraulic reaction and frictional resistance. of the vane with respect to the hollow ring is continually changing by virtue of changing duct or passage areas. Influenced by a low static and velocity source, the relative movement will lbe small, whereas with a large static and velocity source, the movement will be accordingly somewhat larger. 'I'he approximate relative positions at a number of selected points throughout the pump cycle is shown in Figures 4 to 11.

There are three hydraulic actions that tend to move the hollow ring through its orbit. They are, first, the one just mentioned in reference to the static and velocity sources; second, the skin friction in the interior of the hollow ring; and third, the directional change when the liquid is delivered into the expanding circular raise on the high pressure side of the pump. The chief influence determining the relative positioning of the vane and ring is the flow of pressure iluid through the passageway between the bevelled Hydraulically, the angular relation .v

' openings of the working chamber portions are 6 edges 51 and 88 of the ring and the bevelled flanges 51 and 68' at the outer edge of the vane. In other words the areaof the inlet and outlet functions of the pressure of the fluid medium. There is a continual relative angular or rotational movement between the hollow sleeve and the vane, dueto the constantly changing duct areas with the resultant variable pressure relationships.

To make this phenomenon somewhat clearer, let it be assumed that the pump is operating very slowly and employing a gaseous medium. Under these conditions, there would be little or no fluid drive, but the hollow sleeve would be mechanically driven or dogged around its orbit by the impeller-vane. With increasing speed, the gaseous medium, due to pressure being built up in the apparatus, would tend to separate the abutting edges or driving contacts between the vane and the sleeve. With increased pressure existing in the hollow sleeve ducts, the pressure medium is urged to escape, of course, by way of the line of least resistance, which is through the centrifugal chamber and thus through the exhaust pipe I9. when the pressure medium passes from the hollow ring into the centrifugal exhaust chamber further insures the fluid pressure drive just described.

Now with a hydraulic pressure fluid, this phenomenon is even more pronounced and asserts itself at a much lower speed of revolution than in the case of a gaseous medium. Thus, it will be seen that the relative position of the vane and the sleeve varies continually during operation of the pump. This is clearly shown in Figures 4-11 of the drawings. These elements come into actual contact only momentarily as at the point illustratedin Figure 9, and this instantaneous contact is not considered sufficient to comprise a mechanical driving feature. The shifting or compensating relative movement of the sleeve with respect to the impeller vane is influenced by various factors, the speed of opera.. tion, the pressure potential, the specific gravity of the fluid, and to some slight extent by friction.

Now, in considering ther relative movement of the impeller hub r,and the vane, it will be seen that the rolling contact between these mutually engaging surfaces will be compounded of both rolling' and sliding movement. In the embodiments of the invention disclosed herein, no seals are provided between the surfaces in question, except for the end seal device 11, which has been described. Instead, there is provided a series of fine longitudinal grooves 80 in the outer cylindrical-surface of the hub 30. These are clearly shown in Figures 12, 13, and 14 of the drawings, in which the basic elements of the pump are indicated by the same reference numerals as in the earlier described gures of drawing. In thus deliberately dispensing with seals for this rolling contact feature, friction has been reduced and the over-all efficiency of the pump improved in spite of some back-seepage taking place.

In reference to this seepage, it should be pointed out that for both sealing and lubricating purposesY some of the liquid from the high pressure portions of the pump is allowed to move through certain of the ne clearances back to the low pressure side. This is in addition to the pressure vents 63 and 55 already described. For example,

75 in the embodiment illustrated in Figures 12 and The skin friction and reaction 13, a ne duct 83 nnects the groove 82 withv the interior chamber 3l of the hub. A similar lubricating and sealing feature is provided in connection with the oating bushings 5.5 and 56. The

bushing 55 toward its outer edge is provided with an annular groove 85 and this groove is connected with the annular groove 82 by means of the radial duct 81 passing through the bushing. Similarly the bushing 56 is provided with an annular groove 86 toward the outer edge of its outer periphery and a duct 88 leads through the bushing to the inner periphery whereby any minor seepage may pass around the end of the hub 3B',

'packing or wiping member 9i) is provided with an arcuate wiping surface which contacts the outer surface of the ring e5 and serves to remove any abrasive particles which might have entered the pump with the working liquid. Otherwise foreign material might have a tendency to roll by the tangential contact point between the hollow ring and the pump housing wall with resultant damage to the working surface.

In order to apply the wiping member against the surface of the ring at regulated degrees of pressure, a by-pass conduit is provided leading to the recess 9i behind the wiper 98 from either the highV pressure or the low pressure side of the pump. The pump housing is drilled as at 92 to tap off a portion of the lune-shaped chamber L, a horizontal bore 93 is provided, and another radially disposed bore M enters the recess 9i. The ends of the substantially radial bores 92 and 9d are closed respectively by the plugs 85 and 96. In the outer end of the cross bore 93 there is provided an adjustable valve member 91 which is threaded into the bore and has an operative end which regulates the opening from the bore 92. A lock nut 98 serves to secure the valve element 91 in its set position. Thus, pressure iiuid may be taken from appropriate points in the system to apply regulated pressure against the wiper element 90. Without such pressure regulation the sealing member 90 would have to be replaced more frequently.

Another feature illustrated in Figure 14 of the drawings concerns the mounting of the vane 32 with relation to the hub 30 and the housing chamber wall 31. In this case the inner portion of the vane 32' adjacent one side thereof is extended inwardly as at |00 and is skeletonized being provided with one or more openings lill therethrough. The inner end of the extension i0!! approaches the inner wall of the clip or key 34' and may be guided by a ledge 34a provided on this clip.

The key slots 33' within which the edges of the clip 34 are received are spaced inwardly from the inner wall of the hub, in this embodiment and the edges of the cylindrical 'spring key or clip 34' are forced slightly inwardly to enter these slots. results in the exertion of spring pressure outwardly upon the vane 32 and proof the chamber I l, at the continually changing point of'contact 88.

It will be understood from the foregoing that there has been provided by the present invention, a well-balanced, anti-friction drive, cantilever shaft. rotary pump, having cooperating sealing-off lubricating, and minor supporting and guiding means for the shaft-carried impeller organization within the working chamber at points spaced from the anti-friction bearings which afford the principal support or fulcrum x of the shaft. Although for purposes of convenvides means for compensating for wear on the outer surface of the vane or the inner surface 8T ience of illustration, certain of the contributing improvements comprising the present invention, have been illustrated individually in separate iigures of drawing, it is to be clearly understood that they all cooperate to attain the stated advantages of the invention and may be, and for maximum emciency are expected to be, combined in a single pump, even though, of course, partial advantage of the invention may be attained by the transporting of the several features into pumps of this and other types and construction.

Various changes and modifications Amay be made in the embodiments illustrated and described herein without departing from the scope of the invention as defined by the sub-joined claims.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

v4f1. In a rotary pump of the class described a casing having a cylindrical working chamber therein an anti-friction bearing assembly carried by said casing upon one side of said chamber a driving shaft rotatably supported intermediate its length by said bearing assembly one end of the shaft extending outwardly of the bearing assembly upon one side thereof and the other end of the shaft extending from the bearing assembly in the opposite direction into the working chamber, an impeller hub carried on the latter end within the chamber said anti-friction bearing assembly in the casing serving as the. main bearing to take the major radial thrust of the shaft but said other or working end of the shaft-and-impeller combination being otherwise guided in the casing as in the following arrangement: a radial vane carried by said impeller hub and means for resiliently urging it against the inner wall of the working chamber of the casing; bearing surfaces in the casing disposed eccentrically of the shaft and impeller hub; a cylindrical sleeve -rotatably mounted in said bearing surfaces; at least one bearing bushing having mutually eccentric inner and outer bearing surfaces, said bushing being inserted between the eccentrically related impeller hub and sleeve; means keying said bushing to the casing to maintain it stationary during operation; a system of seepage clearances and ducts leading from the working chamber to the subsidiary bearing surfaces of the hub, sleeve, and bushing to seal and lubricate them; and additional sealing means in the working chamber between the sleeve and the hub and between the casing wall and the sleeve.

2. In a rotary pump of the class described, a casing having a cylindrical working chamber therein, an anti-friction bearing assembly carried by said casing upon one side ofsaid chamber, a driving shaft rotatably supported intermediate its length by said bearing assembly, one end of the shaft extending outwardly of the bearing assembly upon one side thereof and the other endof the shaft extending from the bearing'assembly in the opposite direction into the working chamber, an impeller hub carried on the latter end within the chamber, said anti-friction bearing assembly in the casing serving as the main bearing vto take the major radial thrust of the shaft but said other or working end of the shaft-and-impeller combination /being otherwise guided in the casing as in the following arrangement: a radial vane carried by said impeller hub and adapted to revolve-in the working chamber; bearing surfaces in the casing disposed eccentrically of the shaft and impeller hub; a cylindrical sleeve rotatably mounted in said bearing surfaces; at least one bearing bushing having mutually eccentric inner and outer bearing surfaces, said bushing being inserted between the impeller hub and the eccentric sleeve; and a system of seepage clearances and ducts leading from the working chamber to the subsidiary bearing sur.- faces of the hub, sleeve, and bushing to seal and lubricate them.

3. In a rotary pump of the class described, a casing having a cylindrical working chamber therein, an anti-friction bearing assembly carried by said casing upon one side of said chamber, a driving shaft rotatably -supported intermediate its length by said bearing assembly, one end of the shaft extending outwardly of the bearing assembly upon one side thereof and the other end of the shaft extending from the bearing assembly in the opposite direction into the working chamber, an impeller hub carried on the latter end within the chamber, said anti-friction bearing assembly in the casing serving as the main bearing to take the major radial thrust of the shaft but said other or working end of the shaft-v and-impeller combination being otherwise guided in the casing as in the following arrangement: a radial vane carried by said impeller hub and adapted to revolve in the working chamber; bearing surfaces in the casing disposed eccentrically of the shaft and impeller hub; a cylindrical sleeve rotatably mounted in said bearing surfaces; and a system of seepage clearances and ducts leading from the working chamber to the subsidiary bearing surfaces of the hub and sleeve to seal and lubricate them.

4. In a rotary pump of the class described, a casing having a cylindrical working chamber therein, an anti-friction bearing assembly carried by said casing upon one side of said chamber, a driving shaft rotatably supported intermediate its length by said bearing assembly, one end of the shaft extending outwardly of the bearing assembly upon one side thereof and the other end of the shaft extending from the bearing assembly in the opposite direction into the working chamber, an impeller hub carried on the latter end within the chamber, said anti-friction bearing assembly in the casing serving as the main bearing to take the major radial thrust of the shaft but said other or working end of the shaft-and-impeller combination being otherwise guided in the casing as in the following arrangement: a radial vane carried by said impeller hub and adapted to revolve in the working chamber; bearing surfaces in the casing disposed eccentrically of the shaft and impeller hub; a cylindrical sleeve rotatably mounted in said bearing surfaces; at least one bearing bushing having mutually eccentric inner and outer bearing surfaces, said bushing being inserted between the impeller hub and the eccentric sleeve; a system of seepage clearances and ducts leading from the working chamber to the subsidiary bearing surfaces of 10 the hub, sleeve, and bushinf to seal and lubricate them; and additional sealing means in the working chamber between the sleeve and the hub and between the casing wall andi-the sleeve.

o. 1n a rotary pump oi' tne ciass described, a casing having a, cylindrical working chamber therein, an anti-friction bearing assembly carried by said casing upon one side of the said chamber, a driving shaft rotatably supported intermediate its length by said bearing assembly, one end of the shaft extending outwardly of the bearing assembly upon one side thereof and the other end of the shaft extending from the bearing assembly in the opposite direction into the working chamber, a hoilow substantially cylindri- .cal impeller hub carried on the latter end within the chamber, said anti-friction bearing assembly in the casing serving as the main bearing to take the maior radial thrust of the shaft, said other or working end of the shaft and impeller combination being otherwise guided in the casing, a hollow radial vane carried by said inipeller hub, means supporting the vane on the hub for intercommunication between the interiors thereof, an opening in said vane communicatnig with said chamber, means for resiliently urging said vane`from said hollow hub toward and against the inner wall of the working chamber of the casing, while at the same time maintaining said intercommunication, means for introducing fiuid to the interior of said hub, and means for driving said shaft.

6. In a pump of the class described, a casing enclosing a working chamber, a hollow substantially cylindrical impeller hub disposed axially within said chamber, means for rotating said impeller hub, an opening in the wall `of said impeller hub, an impeller vane secured within said opening and extending radially outwardly to l sweep through the working chamber in operation, a, shank portion of said vane projecting within the interior of said hub, said shank portion having side walls, means for securing said vane to said hub comprising key grooves formed in said side walls within the interior of said hub, and a nearly cylindrical keying clip sprung into` the interior of the hub and having its inwardly directed edges inserted in said key grooves.

7. In a pump as set forth in claim 6, means for urging the vane resiliently outwardly against the inner wall of said working chamber, which means requires the keying grooves to be spaced from the inner wall of the hollow hub adjacent the opening in said hub wall and the keying clip to be so sprung into the interior of the hub and into the grooves of the vane that it urges the vane resiliently in a radial direction through the hub opening.

8. The arrangement set forth in claim 6 in which the shank portion of said vane extends into the hollow hub approximately to the far wall of the interior thereof, and is of interrupted skeletonized structure.

9. In a pump as set forth in claim 6, means for urging the vane resiliently outwardly against the inner wall of said working chamber, which means requires the keying grooves to be spaced il mately to the opposite wall, and seating means in the bight of the clip for said shank end.

10. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted within said casing .and co-axially therewith, said impeller member :comprising a central substantially cylindrical hub forming a substantially annular working space of uniform radius between the hub and the inner circumferential wall or said casing, an annular sleeve eccentrically surrounding said impeller hub, said sleeve being internally tangent to said hub and externally tangent to said inner wall of the casing and free to rotate about its own center with the points of tangency substantially xed at diametrically opposite sides of the axis of the casing, whereby said working space is divided into two chambers the cross sections oi which comprise complementary oppositely racing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub, said vane passing through said slot in said sleeve with its outer end having a sliding fit with the inner peripheral wall of the casing, whereby the rotation of the impeller member and the sleeve causes a progressive and alternate division of the respective luneshaped chambers into successively waxing and waning iiuid receiving and uid discharging portions, the discharging portions in the case of both chambers being in advance of said vane and the receiving portions rearward thereof considering the direction of rotation, a fiexible, pliable, wiping seal element seated in a recess in the inner wall of the working chamber at the point of sliding contact between the sleeve and said wall, a duct leading from a portion of the working chamber of the pump to said recess behind said element, an adjustable valve in said duct whereby the admission' of pressure uid behind said element may be regulated to vary the wiping pressure against said sleeve, means for supplying uid to and venting it from said respective portions ci the chambers, and means for driving said impeller member.

ll. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted within said casing and co=axiallyv therewith, said impeller member comprising a central substantially cylindrical hub forming a substantially annular working space of uniform radius between the hub and the inner circumferential wall of said casing, an annular sleeve eccentrically surrounding said impeller hub, said sleeve being internally tangent to said hub and externally tangent to said inner wall of the casing and free to rotate about its own center with the points of tangency substantially iixed at diametrically opposite sides of the axis of the casing, whereby said Working space is divided into two chambers the cross sections of which comprise complementary oppositely facing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub and constituting the edective moving part of the impeller member,

Y l2 vance of said vane and the receiving portions rearward thereof considering the direction of rotation, a ilexible, pliable, non-metallic, nonabrasive, wiping element seated in a recess in the inner wall of the working chamber at the point of sliding contact between the sleeve andsaid wall, a duct leading from a high pressure portion of the working chamber of the pump to said recess behind said element, an adjustable valve in said duct whereby the admission of pressure uid behind said element may be regulated to vary the wiping pressure against said sleeve, means for supplying iiuid to and venting it from said respective portions of the chambers, and means for driving said impeller member.

l2. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted within said casing and co-axially therewith, said impeller member comprising a central substantially cylindrical hub forming a substantially annular working space of uniform radius between the hub and the inner circumferential wall of said casing, an annular sleeve eccentrically surrounding said impeller hub, said sleeve being internally tangent to said hub and externallytangent to said inner wall of the casing and free to rotate about its own center with the points of tangency substantially fixed at diametrically opposite sides of the axis of the casing, whereby said working space is divided into two chambers the cross sections of which comprise complementary oppositely facing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub and constituting the effective moving part of the impeller member, said vane passing through said slot in said sleeve with its outer end having a sliding t with the inner peripheral wall of the casing, whereby the rotation of the impeller member and the sleeve causes a progressive and alternate division of vthe respective lune-shaped chambers into successively waxing and waning iiuid receiving and :fluid discharging portions, the discharging portions in the case of both chambers being in advance of said vane and the receiving portions rearward thereof considering the direction of said vane passing through said slot in said sleeve rotation, accurately tted sealing surfaces on the respective inner and outer margins of the slot within said sleeve upon both sides of the vane, upon the outer side edge of the vane, and upon the portions of the hub adjacent the root of the vane, the'sealing surfaces on the outer margins of said slot comprising bevelled portions on the sleeve, overhanging portions at the outer side edges of the vane, and the sealing surfaces at the last named places comprising bevelled portions on the undersides of said overhanging portions and adapted to seat upon said ilrst named bevelled portions at a point during the operation of the pump, means for supplying uid to and venting it from said respective portions of the chambers, and means for driving said impeller member.

13. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted within said casing and coaxially therewith, said impeller member comprising a central substantially cylindrical hub forming a substantially annular working space of uniform radius between the hub and the inner circumferential wall of said casing, an eccentrically disposed annular sleeve surrounding said impeller hub, said sleeve being internally tangent to 1said hub and externally tangent to said inner wall of the casing and free to rotate about itsl positely facing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub and constituting the effective moving part of the impeller member, said vane passing through said slot in said sleeve with its outer end having a sliding fit with the inner peripheral wall of the casing, whereby the rotation of the impeller member and the sleeve causes a progressive and alternate division of the respective lune-shaped chambers into successively waxing and waning fluid receiving and fluid discharging portions, the discharging portions in the case of both chambers being in advance of said vane and the receiving portions rearward thereof considering the direction of rotation, accurately tted sealing surfaces on the respective inner and outer margins of the slot within said sleeve upon both sides of the vane, upon the outer side edge of the vane, and upon the portions of the hub adjacent the root of the vane, means for supplying fluid to and venting it from said respective portions of the chambers, and means for driving said impeller member, a resilient strip sealing element having one edge secured to the hub near the root of the vane and sprung outwardly to be contacted by the inner portion of the sleeve when the parts are in position where the vane is fully projected through the opening in the sleeve and substantially bisects the outer larger lune.

14. In a rotary pump of the class described. a casing having a cylindrical working chamber therein, an anti-friction bearing assemblycarried by said casing upon one side of saidchamber, a driving shaft rotatably supported intermediate its length by said bearing assembly, one end of the shaft extending outwardly of the bearing assembly upon one side thereof and the other end of the shaft extending from the bearing assemblyA in the opposite direction into the working chamber, an impeller hub carried on said latter end within the chamber, said anti-friction bearing assembly in the casing serving as the main bearing to take the major radial thrust of the shaft but said other or working end of theshaft and impeller combination being otherwise guided in the casing as in the following arrangement: a radial vane carried by said impeller hub and adapted to revolve in the working chamber, bearing surfaces in the casing disposed eccentrically of the shaft and impeller hub, a cylindrical sleeve rotatably mounted in said bearing surfaces; at least one bearing bushing having mutually eccentric inner and outer bearing surfaces, said bushing being inserted between the impeller hub and the eccentric sleeve adjacent the ends thereof, the intermediate cylindrical surfaces of said hub member and said sleeve member being in partly rolling and partly sliding contact during operation of the pump, and a plurality of longitudinal grooves provided in the contacting surface of one of said members to provide a liquid seal.

15. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted Within said casing and co-axially therewith, said impeller memben comprising a Ycentral substantially cylindrical space of uniform radius between the hub and thel inner circumferential wall of said casing, an eccentrically disposed annular sleeve surrounding said impeller hub, said sleeve being internally tangent to said hub and externally tangent to said inner wall of the casing and free to rotate about its own center with the points of tangency Y substantially fixed at diametrically opposite sides of the axisof the casing, whereby said working space is divided into two chambers the cross sections of which comprise complementary oppositely facing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub and constituting the principal effective moving part of the impeller member, said vane passing through said slot in said sleeve with its outer end having a sliding fit with the inner peripheral wall of the casing, said slot being of a width somewhat greater than the thickness of the vane at the portion of the latter which passes through the slot, whereby the rotation of the impeller member and the sleeve causes a progressive and alternate division of the respective lune-shaped chambers into successively waxing and waning fluid receiving and fluid discharging portions, the discharging portions in the case of both chambers being in advance of said vane and the lreceiving portions rearward thereof considering the direction of rotation,

means forsupplying iiuid to said respective rei ceiving portions of the chambers, said annularA sleeve being pr'vided with a longitudinal pas-A1 sageway open to both chambers on the forward siderof said vane, a somewhat restricted outlet in said casing continually in communication with said passageway, and means for driving said impeller, all whereby the velocity of the fluid entering the passageway in the sleeve is greater than thatV of the sleeve itself so that there is van absorption of energy sufficient to carry the sleeve around its orbit Without being pushed by the vane.

16. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted within said casing and co-axially therewith, said impeller member comprising a central substantially cylindrical hub forming a substantially annular working space of uniform radius between the hub and the inner circumferential wall of said casing, an eccentrically disposed annular sleeve surrounding said impeller hub, said sleeve being internally tangent to said hub and externally tangent to said inner wall of the casing and free to rotate about its own center with the points of tangency substantially xed at diametrically opposite sides of the axis of the casing, whereby said working space is divided into two chambers the cross sections of which comprise complementary oppositely facing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub and constituting the effective moving part of the impeller member, said vane passing through said slot in said sleeve with its outer end having a sliding t with the inner peripheral wall of the casing, said sl'ot being of a width somewhat greater than the thickness of the vane at the portion ofthe latter which passes through the slot, the rotation of the impeller member and the sleeve causing a progressive and alternate division of the respective lune-shaped chambers into successively waxing and waning fluid receiving and fluid discharging portions, the discharging portions in the case hub forming a substantially annular working Il of both chambers being in advance of said vane and the receiving portions rearward thereof con.

sidering the direction of rotation, means for supv plying fluid to the receiving portions, said annuv of restricted cross-section in one end of said sleeve for discharging iluid from said annular chamber longitudinally outwardly of the working chamber, whereby a certain back pressure is established for causing the vane to drive the sleevethrough fluid pressure alone under normal steady conditions of operation, and means for driving said impeller member.

1'7. A rotary pump comprising, in combination, a substantially cylindrical casing, an impeller member rotatably mounted within said casing member rotatablymounted within said casing and co-axially therewith, said impeller member comprising a central substantially cylindrical hub forming a substantially annular working space of uniform radius between the hub and the inner circumferential wall ofv said casing, an eccentrically disposed annular sleeve surrounding said impeller hubl said sleeve being internally tangent to said hub and externally tangent to said in ner wall of the casing and free to rotate about its own center with the points of tangency substantially xed at diametrically opposite sides of the axis of the casing, whereby said working space is divided into two chambers the cross sections of which comprise complementary oppositely lacing interlocking lunes, an axially extending slot in said sleeve, a radially extending vane carried by said hub and constituting the principal effective moving part of the impeller member,

said vane passing through said slot in said sleeve with its outer end having a sliding t with the inner peripheral wall of the casing, said slot being of a Width somewhat greater than the thickness of the vane at the portion of the latter which passes through the slot, whereby the rotation of the impeller member and the sleeve causes a progressive and alternate division of the respective lune-shaped chambers into successively waxing and waning fluid receiving and fluid discharging portions, the discharging portions in the case of both chambers being in advance of said vane and the receiving portions rearward thereof considering the direction of rotation, means for supplying uid to said respective receiving portions of the chambers, said annular sleeve being provided with a longitudinal passageway open to both chambers on the forward side o! said vane, a somewhat restricted outlet in said casing continually in communication with said passageway, and means for driving said impeller, al1 whereby the sleeve during substantially its entire operative movement is moved about its orbit by fluid pressure without actual driving contact with the vane, the spacing of the vane from the edges of the slot in the sleeve, and thus the areas of the openings to and from said portions of the luneshaped chambers, being free to vary during operation under the inuence of the pressure po'- tentiai, the hydraulic reaction, and frictional resistance.

ERIK G. SEASTROM.

REFERENCES CITED The following references are of record in the 

